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(Model.)

E. T. STARR.

DENTAL T001. HOLDER.

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' Ntra STATES PATENT rtree.,

ELI T. srAnR, oF PHILADELPHIA,

PENNSYLVANIA, ASSIGNOR TO KJAMES W.

WHITE, JAMES CLARENCE V'HITE, AND H. M. LEWIS, TRUSTEES, ALL OF SAME PLACE.

DENTAL-TOOL HOLDER.

SPECIFICATION forming part of Letters Patent No. 248,958, dated November 1, 1881. Application filed June 30, 1881. (Model.)

To all whom t may concern.

Be it known that I, ELI T. STARR, of the city and county of Philadelphia, in the. State of Pennsylvania, have invented certain new and usefulImproveinentsin Dental-EngineBit or Tool Holders, of which the following is a specification.

There are generally a large number of operating bits or tools for use interchangeably with 1o the hand-piece of a dental engine, the chuck of the hand-piece, which revolves in suitable bearings in the hand-piece casing, having its front end socketed for the reception of the notched shanks ofthe bits or tools. The working-points of these bits or tools vary in their character, owing to the different kinds of work they are required to perform, and probably, in

working upon a single tooth, the dentist may have to change his operating hit or tool a half zo dozen times.

The object of my present invention is to provide for the removal ofthe bitor tool from the spindle-chuck of the hand-piece without necessitatingthe use of the operators fin gers for that purpose, and without stopping `the rotation ofthe chuck, and at the same timeto avoid the necessity for the use of the operators fingers in placing the shank of a tool in the chuck-socket, whether the chuck is being rotated or remains at rest in its bearings.

The subjectmatter claimed is particularly pointed out at the close of the specification.

In the accompanying drawings, which show my improvements, Figure lis a side view, and 3 5 Fig. 2 a front view, of the holder.

The base or block A may have steps or ledges a a c, one above the other, on its upper surface, and on each step or ledge is a row of spring-holders, B. Three rows ot' spring-hold ers, with ten holders, to the row would probably be am plysuflicientin capacity, as that number of spring-holders would hold probably all the bits or tools with operating-points of different character in daily use by the dentist of 4 5 large practice.

I have shown in the drawings only two rows of spring-holders, with eight holders to each row. The number of spring-holders employed and their arrangement in rows or series will be of the square form, shown in Fig.

according to tasto or convenience. I prefer 5o each row of holdcrsB to be mounted upon a plate, C, detachably connected (by screws, for example) with a base, A, so as to be removable independently, if desired, t'or any purpose.

Each of said spring-holders B consists of two :5 plate-spring arms or jaws, b I), rising vertical- V ly from the plate C, and having their lower ends united or closely joined, so that the tendency of the arms or jaws will be to remain close together, and so that anything which 6o opens said arms or jaws by passing between them will be grasped or held by them, owing to their resiliency. The upper or free ends of said arms orjaws b b are bent outward or liaring, so as toforin a eomparativel,1 wide mouth to receive an enlargement, d, on the bit or tool shank D, and permit said enlargement to be readily forced down to spread apart the jaws and pass into a seat or socket, b, in the springholder and rest therein with the jaws grasping 7o the shank. An opening or recess, preferably 1, is cut or formed in the side walls ot' the seat or socket b of the plate-spring` arms or jaws I), so that the tool-enlargement may rest in its seat in the holder without forcing the jaws thereof too far apart or necessitating the enlargement of the walls of the seat or socket. Moreover, by forming the openings or recesses in the side walls of the seat b', the spring-arms take a 8o posit ive hold of the tool-enlargement upon both sides, and prevent endwise movement of the tool by either a thrust or pull, thus enabling me to provide a holder to operate in the manner hereinafter described in extracting a tool from or inserting one in the chuck of a dentalengine hand-piece.

When the enlargement on the toolshank is of cone shape, as shown and claimed in Johnston and BrownesPatent,N0.213,662, ofMarch 9o 25,1879,Iprefer the daring mouth ofthe spring` holder to be shaped as shown in the lower row of holders, marked l in the drawings.

The manner in which a bit ortool shank is held in the holder is clearly shown. It will 95 also be seen that the plates C, which I preferably employ to carry the spring-holders, are so fastened to the hase A that the holders are slightly tilted or inclined out of the perpendicular, which is for the purpose of throwing the notched driving ends ot' the tool'shanks a little higher up from the base than would be the case were thel springholders exactly per- 1 )endicular. Moveover, this inclination of the spring'holders enables the tool to be more easily removed from the chucksocket, as it gives the holder a better action on the tool-enlargement.

The operation ot' the holder is as follows: Suppose, in using a dental-engine hand-piece, such,t'or instance, as the one shown in Letters Patent granted to me October 26, 1880, as No. 233,709, modified to receive tools having a conical enlargement, as described herein, a tool with a working point or end of peculiar' character has been used, and it is desired to rapidly remove the tool without stopping the engine or the rotation of the chuck and to insert in the chuck socket another tool with a working point of diii'erent character or size, allthat is necessarv1 is to rock the lever ot' said hand-piece, which controls the tool -t'astening devices ot' the chuck, so as to release the fastenincs from the tool-shank and then engage the tool-shank, in advance otl the nose of the hand-piece, with the spring-holder until the enlargement on the tool is permitted to tit and be pressed into the flaring mouth ot' the sprin ghold er, and thencein to the seat or socket b below, the arms or jaws of the holder being sprung apart for the purpose. As soon as the tool-enlargement is pressed into its seat in the spring-holder said holder will grasp it and hold the tool lirmlyenough to withdraw it from the chuck as the handfpiece is moved or drawn back. WVhen removed the tool will be held by the holder, as shown in the drawings.

To insert a tool in the socket ot' the chuck, move the handpiece up to the tool-shank so as to enter said shank in the socket a distance t'ted, moved, to disengage it from sufiicient to enable the tool to be li or forced upward so as ll i i l the spring-holder. hen hold the hand-piece in a vertical position with its nose or front end upward. This position, owing to the revolution of the chuck, will canse the tool to move into its place in the socket for the engagement of the tool-locking devices with its notched ends, which devices are then permitted to close upon the tool-shank and lock it securely in the chuck, with which it is driven firmly and steadily to do its work.

rEhe removal and insertion ot a tool can be accomplished with exceeding rapidity and withoutthe use of the operators tingers to take hold of the tool, thus leaving his hand free to do other necessary work about the patient.

I do not claim herein, broadly, a spring-holder composed of two spring-arms having atlaring mouth and a seat for the article to be held, nor a series of such holders arranged in a row upon a base or block. Such devices have long been in common use as pen -racks, &c., but they have never before, so far as I am aware, been organized for the purpose of holding rotary engine tools orbits, and ot' operatingtherewith in the manner set out by me. The open ings or recesses in the sides of the spring-jaws to tit around the tool-enlargement are a necessary feature in my invention.

I claim as my invention- The spring -holder for engine bits or tools, constructed, substantially as hereinbefore set forth, ot' two spring-jaws the side wallsof which are provided with openings or recesses to receive the enlargement ot' the toolshank and tirmly grasp it so as positively to prevent endwise. movement of the tool,

In testimony whereof 1 have hereunto subscribed my name this 28th day of June, A. D. 1881.

ELI T. STARR.

Vitnesses FRANK L. HIsE, ALBERT P. toom. 

